The present invention is directed to an optical mixing element wherein a mixing stage extends between an incoming group and an outgoing group of light conducting fibers.
In optical communication systems, in particular, in data bus configurations of a T-or star structure, optical mixers play a decisive role. Their function is to make available data transmitted by any one of n-terminal devices communicating with one another to all the other terminal devices with an intensity which is as equal as possible.
A mixer or mixing element of the type which extends between an incoming group of fibers and an outgoing group of fibers which is suitable for the above purposes is known and disclosed in an article by Marshall C. Hudson and Frank L. Thiel, "The Star Coupler: A Unique Interconnection Component for Multimode Optical Waveguide Communication Systems", Applied Optics, Vol. 13, No. 11, November 1974, pages 2540-2545. In this article, a mixer stage, which comprises a cylindrical glass rod having end surface abutting against the groups of fibers is disclosed. However, this mixer has high insertion losses of 6 to 8 dB and also does not ensure a sufficiently uniform distribution of power to the outgoing fibers.